Understanding the alkyl effect of geminal dinitropropyl ester energetic plasticizers on hydroxyl terminated polybutadiene(HTPB):Simultaneous tuning on low temperature behavior and processability

Geminal dinitropropyl ester plasticizers(DNPEPs) possess excellent energetic performances which provide good potentials as insensitive plasticizer. In this study, we design and synthesize DNPEPs with different alkane chain parts, and systematically investigate their structure-property relationships.Results show that DNPEPs have impact sensitivities all higher than 25.2 J, thermal decomposition temperatures all higher than 254 ℃, and glass transition temperatures(T_(g)) lower than-90 ℃.Furthermore, the effects of DNPEPs as plasticizer are studied on hydroxyl terminated polybutadiene(HTPB) in detail, including the viscosity, glass transition temperatures and others. It is noteworthy that 2,2-dinitropropyl nonanoate(DNPNc) among these DNPEPs exhibits the most expected simultaneous tuning effects on both viscosity and T_(g) of HTPB systems, providing favorable potentials to replace the conventional plastizers as dioctyl sebacate(DOS) in the HTPB based propellants and explosives.

Evaluation of human epidermal growth factor receptor 2 status of breast cancer using preoperative multidetector computed tomography with deep learning and handcrafted radiomics features

Objective:To evaluate the human epidermal growth factor receptor 2(HER2)status in patients with breast cancer using multidetector computed tomography(MDCT)-based handcrafted and deep radiomics features.Methods:This retrospective study enrolled 339 female patients(primary cohort,n=177;validation cohort,n=162)with pathologically confirmed invasive breast cancer.Handcrafted and deep radiomics features were extracted from the MDCT images during the arterial phase.After the feature selection procedures,handcrafted and deep radiomics signatures and the combined model were built using multivariate logistic regression analysis.Performance was assessed by measures of discrimination,calibration,and clinical usefulness in the primary cohort and validated in the validation cohort.Results:The handcrafted radiomics signature had a discriminative ability with a C-index of 0.739[95%confidence interval(95%CI):0.661-0.818]in the primary cohort and 0.695(95%CI:0.609-0.781)in the validation cohort.The deep radiomics signature also had a discriminative ability with a C-index of 0.760(95%CI:0.690-0.831)in the primary cohort and 0.777(95%CI:0.696-0.857)in the validation cohort.The combined model,which incorporated both the handcrafted and deep radiomics signatures,showed good discriminative ability with a C-index of 0.829(95%CI:0.767-0.890)in the primary cohort and 0.809(95%CI:0.740-0.879)in the validation cohort.Conclusions:Handcrafted and deep radiomics features from MDCT images were associated with HER2 status in patients with breast cancer.Thus,these features could provide complementary aid for the radiological evaluation of HER2 status in breast cancer.

An active vibration control method based on energy-fuzzy for cantilever structures excited by aerodynamic loads

In wind tunnel tests for the full-model fixed with sting,the low structural damping of the long cantilever sting results in destructive low-frequency and large-amplitude vibration.In order to obtain high-quality wind tunnel test data and ensure the safety of wind tunnel tests,an energy-fuzzy adaptive PD(Proportion Differentiation)control method is proposed.This method is used for active vibration control of a cantilever structure under variable aerodynamic load excitation,and real-time adjustment of parameters is achieved according to the system characteristics of vibration energy.Meanwhile,a real-time method is proposed to estimate the real-time vibration energy through the vibration acceleration signal,and the average exciting power of aerodynamic load is obtained by deducting the part of the power contributed by the vibration suppressor from the total power.Furthermore,an energy-fuzzy adaptive PD controller is proposed to achieve adaptive control to the changes of the aerodynamic load.Besides,the subsonic and transonic experiments were carried out in wind tunnel,the results revealed that comparing to fixed gain PD controllers,the energy-fuzzy adaptive PD controller maintains higher performance.

Remote-controlled flexible pose measurement system and method for a moving target in wind tunnel

The measurement of position and attitude parameters for the isolated target from a highspeed aircraft is a great challenge in the field of wind tunnel simulation technology. This paper proposes a remote-controlled flexible pose measurement system in wind tunnel conditions for the separation of a target from an aircraft. The position and attitude parameters of a moving object are obtained by utilizing a single camera with a focal length and camera orientation that can be changed based on different measurement conditions. Using this proposed system and method, both the flexibility and efficiency of the pose measurement system can be enhanced in wind tunnel conditions to meet the measurement requirements of different objects and experiments, which is also useful for the development of an intelligent position and attitude measurement system. The position and the focal length of the camera also can be controlled remotely during measurements to enlarge both the vertical and horizontal measurement range of this system. Experiments are conducted in the laboratory to measure the position and attitude of moving objects with high flexibility and efficiency, and the measurement precision of the measurement system is also verified through experiments.